Prediction of the probability of large fires in the Sydney region of south-eastern Australia using fire weather

2009 ◽  
Vol 18 (8) ◽  
pp. 932 ◽  
Author(s):  
R. A. Bradstock ◽  
J. S. Cohn ◽  
A. M. Gill ◽  
M. Bedward ◽  
C. Lucas

The probability of large-fire (≥1000 ha) ignition days, in the Sydney region, was examined using historical records. Relative influences of the ambient and drought components of the Forest Fire Danger Index (FFDI) on large fire ignition probability were explored using Bayesian logistic regression. The preferred models for two areas (Blue Mountains and Central Coast) were composed of the sum of FFDI (Drought Factor, DF = 1) (ambient component) and DF as predictors. Both drought and ambient weather positively affected the chance of large fire ignitions, with large fires more probable on the Central Coast than in the Blue Mountains. The preferred, additive combination of drought and ambient weather had a marked threshold effect on large-fire ignition and total area burned in both localities. This may be due to a landscape-scale increase in the connectivity of available fuel at high values of the index. Higher probability of large fires on the Central Coast may be due to more subdued terrain or higher population density and ignitions. Climate scenarios for 2050 yielded predictions of a 20–84% increase in potential large-fire ignitions days, using the preferred model.

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Marina D’Este ◽  
Antonio Ganga ◽  
Mario Elia ◽  
Raffaella Lovreglio ◽  
Vincenzo Giannico ◽  
...  

Abstract Background Wildfires play a key role in shaping Mediterranean landscapes and ecosystems and in impacting species dynamics. Numerous studies have investigated the wildfire occurrences and the influence of their drivers in many countries of the Mediterranean Basin. However, in this regard, no studies have attempted to compare different Mediterranean regions, which may appear similar under many aspects. In response to this gap, climatic, topographic, anthropic, and landscape drivers were analyzed and compared to assess the patterns of fire ignition points in terms of fire occurrence and frequency in Catalonia (Spain), Sardinia, and Apulia (Italy). Therefore, the objectives of the study were to (1) assess fire ignition occurrence in terms of probability and frequency, (2) compare the main drivers affecting fire occurrence, and (3) produce fire probability and frequency maps for each region. Results In pursuit of the above, the probability of fire ignition occurrence and frequency was mapped using Negative Binomial Hurdle models, while the models’ performances were evaluated using several metrics (AUC, prediction accuracy, RMSE, and the Pearson correlation coefficient). The results showed an inverse correlation between distance from infrastructures (i.e., urban roads and areas) and the occurrence of fires in all three study regions. This relationship became more significant when the frequency of fire ignition points was assessed. Moreover, a positive correlation was found between fire occurrence and landscape drivers according to region. The land cover classes more significantly affected were forest, agriculture, and grassland for Catalonia, Sardinia, and Apulia, respectively. Conclusions Compared to the climatic, topographic, and landscape drivers, anthropic activity significantly influences fire ignition and frequency in all three regions. When the distance from urban roads and areas decreases, the probability of fire ignition occurrence and frequency increases. Consequently, it is essential to implement long- to medium-term intervention plans to reduce the proximity between potential ignition points and fuels. In this perspective, the present study provides an applicable decision-making tool to improve wildfire prevention strategies at the European level in an area like the Mediterranean Basin where a profuse number of wildfires take place.


2021 ◽  
Author(s):  

Forest and wildland fires are a natural part of ecosystems worldwide, but large fires in particular can cause societal, economic and ecological disruption. Fires are an important source of greenhouse gases and black carbon that can further amplify and accelerate climate change. In recent years, large forest fires in Sweden demonstrate that the issue should also be considered in other parts of Fennoscandia. This final report of the project “Forest fires in Fennoscandia under changing climate and forest cover (IBA ForestFires)” funded by the Ministry for Foreign Affairs of Finland, synthesises current knowledge of the occurrence, monitoring, modelling and suppression of forest fires in Fennoscandia. The report also focuses on elaborating the role of forest fires as a source of black carbon (BC) emissions over the Arctic and discussing the importance of international collaboration in tackling forest fires. The report explains the factors regulating fire ignition, spread and intensity in Fennoscandian conditions. It highlights that the climate in Fennoscandia is characterised by large inter-annual variability, which is reflected in forest fire risk. Here, the majority of forest fires are caused by human activities such as careless handling of fire and ignitions related to forest harvesting. In addition to weather and climate, fuel characteristics in forests influence fire ignition, intensity and spread. In the report, long-term fire statistics are presented for Finland, Sweden and the Republic of Karelia. The statistics indicate that the amount of annually burnt forest has decreased in Fennoscandia. However, with the exception of recent large fires in Sweden, during the past 25 years the annually burnt area and number of fires have been fairly stable, which is mainly due to effective fire mitigation. Land surface models were used to investigate how climate change and forest management can influence forest fires in the future. The simulations were conducted using different regional climate models and greenhouse gas emission scenarios. Simulations, extending to 2100, indicate that forest fire risk is likely to increase over the coming decades. The report also highlights that globally, forest fires are a significant source of BC in the Arctic, having adverse health effects and further amplifying climate warming. However, simulations made using an atmospheric dispersion model indicate that the impact of forest fires in Fennoscandia on the environment and air quality is relatively minor and highly seasonal. Efficient forest fire mitigation requires the development of forest fire detection tools including satellites and drones, high spatial resolution modelling of fire risk and fire spreading that account for detailed terrain and weather information. Moreover, increasing the general preparedness and operational efficiency of firefighting is highly important. Forest fires are a large challenge requiring multidisciplinary research and close cooperation between the various administrative operators, e.g. rescue services, weather services, forest organisations and forest owners is required at both the national and international level.


2008 ◽  
Vol 17 (6) ◽  
pp. 793 ◽  
Author(s):  
Richard J. Williams ◽  
Carl-Henrik Wahren ◽  
Arn D. Tolsma ◽  
Glenn M. Sanecki ◽  
Warwick A. Papst ◽  
...  

The fires of summer 2003 in south-eastern Australia burnt tens of thousands of hectares of treeless alpine landscape. Here, we examine the environmental impact of these fires, using data from the Bogong High Plains area of Victoria, and the Snowy Mountains region of New South Wales. Historical and biophysical evidence suggests that in Australian alpine environments, extensive fires occur only in periods of extended regional drought, and when severe local fire weather coincides with multiple ignitions in the surrounding montane forests. Dendrochronological evidence indicates that large fires have occurred approximately every 50–100 years over the past 400 years. Post-fire monitoring of vegetation in grasslands and heathlands indicates that most alpine species regenerate rapidly after fire, with >90% of species present 1 year after fire. Some keystone species in some plant communities, however, had not regenerated after 3 years. The responses of alpine fauna to the 2003 fires were variable. The core habitat (closed heathland) of several vulnerable small mammals was extensively burnt. Some mammals experienced substantial falls in populations, others experienced substantial increases. Unburnt patches of vegetation are critical to faunal recovery from fire. There was, however, no evidence of local extinction. We conclude that infrequent extensive fires are a feature of alpine Australia. For both the flora and fauna, there is no quantitative evidence that the 2003 fires were an ecological disaster, and we conclude that the flora and fauna of alpine Australia are highly resilient to infrequent, large, intense fires.


2004 ◽  
Vol 13 (2) ◽  
pp. 133 ◽  
Author(s):  
Haiganoush K. Preisler ◽  
David R. Brillinger ◽  
Robert E. Burgan ◽  
J. W. Benoit

We present a probability-based model for estimating fire risk. Risk is defined using three probabilities: the probability of fire occurrence; the conditional probability of a large fire given ignition; and the unconditional probability of a large fire. The model is based on grouped data at the 1 km2-day cell level. We fit a spatially and temporally explicit non-parametric logistic regression to the grouped data. The probability framework is particularly useful for assessing the utility of explanatory variables, such as fire weather and danger indices for predicting fire risk. The model may also be used to produce maps of predicted probabilities and to estimate the total number of expected fires, or large fires, in a given region and time period. As an example we use historic data from the State of Oregon to study the significance and the forms of relationships between some of the commonly used weather and danger variables on the probabilities of fire. We also produce maps of predicted probabilities for the State of Oregon. Graphs of monthly total numbers of fires are also produced for a small region in Oregon, as an example, and expected numbers are compared to actual numbers of fires for the period 1989–1996. The fits appear to be reasonable; however, the standard errors are large indicating the need for additional weather or topographic variables.


2021 ◽  
Author(s):  
Jiaying He ◽  
Tatiana Loboda ◽  
Nancy French ◽  
Dong Chen

<p>Tundra fires are common across the pan-Arctic region, particularly in Alaska. Fires lead to significant impacts on terrestrial carbon balance and ecosystem functioning in the tundra. They can even affect the forage availability of herbivorous wildlife and living resources of local human communities. Also, interactions between fire and climate change can enhance the fire impacts on the Arctic ecosystems. However, the drivers and mechanisms of wildland fire occurrences in Alaskan tundra are still poorly understood. Research on modeling contemporary fire probability in the tundra is also lacking. This study focuses on exploring the critical environmental factors controlling wildfire occurrences in Alaskan tundra and modeled the fire ignition probability, accounting for ignition source, fuel types, fire weather conditions, and topography. The fractional cover maps of fuel type components developed Chapter 2 serve as input data for fuel type distribution. The probability of cloud-to-ground (CG) lightning and fire weather conditions are simulated using WRF. Topographic features are also calculated from the Digital Elevation Model (DEM) data. Additionally, fire ignition locations are extracted from Moderate Resolution Imaging Spectroradiometer (MODIS) active fire product for Alaskan tundra from 2001 to 2019. Empirical modeling methods, including RF and logistic regression, are then utilized to model the relationships between environmental factors and wildfire occurrences in the tundra and to evaluate the roles of these factors. Our results suggested that CG lightning is the primary driver controlling fire ignitions in the tundra, while warmer and drier weather conditions also support fires. We also projected future potential of wildland fires in this tundra region with Coupled Model Intercomparison Projects Phase 6 (CMIP6) data. The results of this study highlight the important role of CG lightning in driving tundra fires and that incorporating CG lightning modeling is necessary and essential for fire monitoring and management efforts in the High Northern Latitudes (HNL).</p>


Fire ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 60
Author(s):  
Joshua Clark ◽  
John T. Abatzoglou ◽  
Nicholas J. Nauslar ◽  
Alistair M.S. Smith

Red Flag Warnings (RFWs) issued by the National Weather Service in the United States (U.S.) are an important early warning system for fire potential based on forecasts of critical fire weather that promote increased fire activity, including the occurrence of large fires. However, verification of RFWs as they relate to fire activity is lacking, thereby limiting means to improve forecasts as well as increase value for end users. We evaluated the efficacy of RFWs as forecasts of large fire occurrence for the Northwestern U.S.—RFWs were shown to have widespread significant skill and yielded an overall 124% relative improvement in forecasting large fire occurrences than a reference forecast. We further demonstrate that the skill of RFWs is significantly higher for lightning-ignited large fires than for human-ignited fires and for forecasts issued during periods of high fuel dryness than those issued in the absence of high fuel dryness. The results of this first verification study of RFWs related to actualized fire activity lay the groundwork for future efforts towards improving the relevance and usefulness of RFWs and other fire early warning systems to better serve the fire community and public.


2012 ◽  
Vol 12 (5) ◽  
pp. 1333-1336 ◽  
Author(s):  
C. Ricotta ◽  
D. Guglietta ◽  
A. Migliozzi

Abstract. Different land cover types are related to different levels of fire hazard through their vegetation structure and fuel load composition. Therefore, understanding the relationships between landscape changes and fire behavior is of crucial importance for developing adequate fire fighting and fire prevention strategies for a changing world. In the last decades the abandonment of agricultural lands and pastoral activities has been the major driver of landscape transformations in Mediterranean Europe. As agricultural land abandonment typically promotes an increase in plant biomass (fuel load), a number of authors argue that vegetation succession in abandoned fields and pastures is expected to increase fire hazard. In this short paper, based on 28 493 fires in Sardinia (Italy) in the period 2001–2010, we show that there is no evidence of increased probability of fire ignition in abandoned rural areas. To the contrary, in Sardinia the decreased human impact associated with agricultural land abandonment leads to a statistically significant decrease of fire ignition probability.


2011 ◽  
Vol 59 (5) ◽  
pp. 295 ◽  
Author(s):  
Jack H. Pascoe ◽  
Robert C. Mulley ◽  
Ricky Spencer ◽  
Rosalie Chapple

South-east Australia has a complex predator assemblage which has historically been vulnerable to introduced species. This is the first Australian field study to analyse samples from members of the families Canidae, Dasyuridae, Strigidae, and Varanidae to describe the diet and diet overlap between these predators. Samples were collected opportunistically and hair and bone analysis was used to identify the content of samples. Wild dogs (Canis lupus) and lace monitors (Varanus varius) predominantly consumed large mammalian prey, which contributed to the high level of diet overlap (Ojk = 0.79) between these two species. Foxes (Vulpes vulpes) and spotted-tailed quolls (Dasyurus maculatus) also had a high level of diet overlap (Ojk = 0.76), a result of their diets containing a high proportion of medium-sized mammals. The diet of wild dogs and foxes showed moderate overlap (Ojk = 0.59), and foxes were more likely to prey on species within the critical weight range than on macropods, which made up a high proportion of the diet of wild dogs. These data confirm that significant diet overlap can occur between predators from different taxonomic classes and further investigation of potential competition will be important to ongoing management.


2003 ◽  
Vol 108 (1) ◽  
pp. 13-32 ◽  
Author(s):  
P.P Hesse ◽  
G.S Humphreys ◽  
P.M Selkirk ◽  
D.A Adamson ◽  
D.B Gore ◽  
...  

2008 ◽  
Vol 17 (6) ◽  
pp. 809 ◽  
Author(s):  
Ross A. Bradstock

Large fires coincident with drought occurred in south-eastern Australia during 2001–2007. Perceptions of large, intense fires as being ecologically ‘disastrous’ are common. These are summarised by four hypotheses characterising large fires as: (i) homogenous in extent and intensity; (ii) causing large-scale extinction due to perceived lack of survival and regeneration capacity among biota; (iii) degrading due to erosion and related edaphic effects; (iv) unnatural, as a consequence of contemporary land management. These hypotheses are examined using available evidence and shown to inadequately account for effects of large fires on biodiversity. Large fires do not burn homogeneously, though they may produce intensely burnt patches and areas. The bulk of biota are resilient through a variety of in situ persistence mechanisms that are reinforced by landscape factors. Severe erosive episodes following fire tend to be local and uncertain rather than global and inevitable. Redistribution of soil and nutrients may reinforce habitat variation in some cases. Signals of fire are highly variable over prehistoric and historic eras, and, in some cases, contemporary and pre-European signal levels are equivalent. The most important effects of large fires in these diverse ecological communities and landscapes stem from their recurrence rate. Adaptive management of fire regimes rather than fire events is required, based on an understanding of risks posed by particular regimes to biota.


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